Research On Guidance Algorithm And Control Law Of Air-to-air Missile

Missile guidance and control system is the core of the missile system.The attacking accuracy of the missile depends on the performance of both missile guidance and control system.In particular,in modem war mode,the operational environment of the missile is complex and changeable,and the effects of external disturbances on missile flight are also increasing in condition of large airspace and high maneuverability.Meanwhile,the development of aviation industry also makes antagonism and maneuverability of interception target stronger.There are more stringent requirements for missile guidance and control system due to the above factors.The missile guidance and control system is designed based on air-to-air missile system.The main contents are as follows:Firstly,the mathematical model of air-to-air missile is built.The common coordinate system and transformation relations among the coordinate systems in missile kinematics analysis are introduced.Then the forces and moments acting on the missile are analyzed.Based on these coordinates,the missile kinematics equation and kinetic equation are built.According to the three-dimensional space movement relationship of missile and target,three-dimensional pursuit and evasion model is derived,which is used in the design process of missile guidance system.In addition,the control system is studied by taking the pitch channel of the missile control system as an example,and the nominal model of the pitch channel of the missile control system is given.Secondly,a terminal guidance law is designed for missile guidance system.Based on internal model principle and backstepping design method,an adaptive internal model guidance law is proposed for the large maneuver or time-varying maneuvering target.In the design process,the target maneuver is regarded as the unknown disturbance generated by an external system.An observer using the internal model principle is designed to estimate the disturbance.The final adaptive internal model guidance law is obtained via combining with the nominal guidance law for the target without maneuver.The stability and accuracy of the proposed method are proved by theoretical analysis.The simulation results show that the closed-loop system can reject the external disturbance asymptotically,and has satisfying guidance performance.Thirdly,one control law is proposed the missile control system.Considering the actual flight scenarios,the uncertainties of the missile control system are modeled based on the nominal model of the pitch channel of the control system,since there are some uncertainties in the aerodynamic coefficient of the missile.Based on this model,robust control law is designed.The simulation results show that the control system has strong robustness to the system uncertainties.In addition,considering the weak actuation effectiveness of aerodynamic fins when the missile is in high altitude,conventional missile is often difficult to respond quickly for the external signal.And the aerodynamic force/direct force distribution strategy was designed by introducing the dual control of aerodynamic lift and lateral jet force.Theoretical analysis and numerical simulation results show that the aerodynamic force/direct force composite control can accelerate the response speed of the system compared with one only relying on the air rudder control.Finally,the research is summarized and some open problems of missile guidance and control systems to be explored are pointed out in future.